This post should really be up on the forum but it doesn't actually provide any firm dates to compare anything with – it more or less says they have the ability, in some circumstances, of C14 dating back as far as 50,000 + years into the past. See www.eurekalert.org/pub_releases/2012-10/haog-asl101912.php and www.eurekalert.org/pub_releases/2012-10/uoo-jl101212.php
The same subject, in detail and with some excellent comments, by Tim Ball for example, can be found at http://wattsupwiththat.com/2012/10/20/new-paleo-calibration-series-done-… and can be found also at various other sites, as an abstract, for example at www.nature.com/news/core-sample-sends-carbon-clock-farther-back-in-time-…